MRIs May Drive More Women to Mastectomy

May 16, 2008

By AUDREY GRAYSONABC News Medical Unit

Women with breast cancer are increasingly opting for mastectomies over lumpectomies, a surgical procedure that removes only the cancerous tumor inside the breast, say researchers at the Mayo Clinic in Rochester, Minn.

The possibility that the growing use of magnetic resonance imaging for diagnosis is partly responsible for this increase is raising new concern over whether women are getting mastectomies needlessly. One leading breast cancer specialist called the MRI-driven boost in mastectomies "alarming."

Mayo Clinic researchers evaluated mastectomy rates at their institution between 1997 and 2006 in relation to the use of preoperative MRI -- a screening tool that is more sensitive than traditional mammography but also more likely to result in false positives for breast cancer.

Researchers sought to answer the question of whether the more sensitive MRI screening test would cause more breast cancer patients, frightened by the lumps and bumps this test picked up inside their breasts, to have the whole breast removed rather than just those lumps that were determined to be cancerous.

They found that among 5,464 women who had surgery for early-stage breast cancer, the mastectomy rates rose between 2003 and 2006, when the number of patients receiving an MRI doubled from 11 percent in 2003 to 22 percent in 2006.

The researchers reported that the number of mastectomies performed at their institution have increased by 13 percent over a period of three years. In 2003, researchers reported that mastectomy accounted for only 30 percent of early-stage breast cancer surgeries. The number rose to account for 43 percent of all breast cancer surgeries in 2006.

Moreover, researchers found that women who received an MRI to screen for breast cancer were significantly more likely to choose a mastectomy than those who did not receive an MRI. More than half of the patients who received an MRI -- 52 percent -- chose to undergo a mastectomy, compared with 38 percent of patients who did not have an MRI.

Technology Influencing Patient Decisions?

Dr. Matthew Goetz, one of the researchers involved in the study and assistant professor of oncology at the Mayo Clinic, said that although the study cannot confirm precisely why so many more women are opting for mastectomies at the Mayo Clinic, it undeniably ties the increase in mastectomy rates to the increased use of MRI.

"New imaging modalities like MRI ... have influenced [the patients'] decision to get a mastectomy," Goetz explained. "For patients who had preoperative MRIs, the mastectomy rate was significantly higher over the whole four-year period."

Many doctors worry that because the MRI test is more sensitive but less specific, it may be responsible for unnecessary surgery to have benign lumps removed and perhaps unnecessary worry.

Dr. Henry Kuerer, professor and director of the Breast Surgical Oncology Training Program at the M.D. Anderson Cancer Center in Houston, said that his own experience has not suggested an increase in mastectomy rates.

"We are not seeing an increase in our mastectomy rates but are seeing increasing women referred to us from the community who are scared to death by frightening MRI reports without appropriate biopsy," Kuerer said.